BIOACTIVE GLASS SHELL GROWTH OF A Si–Na–Ca–P LAYER ON GOLD NANOPARTICLES FUNCTIONALIZED WITH MERCAPTOPROPYLTRIMETHYLOXYSILANE–SILICATE–TETRAETHYLOTHOSILICATE

Calcium phosphate and silicate-modified gold surfaces have potential applications in orthopedic and dental reconstruction, especially when combined with bone cement or dental resins. The aim of this study was to evaluate the formation of a Si–Na–Ca–P glass system nanoshell on functionalized gold nanoparticles. Stable gold nanoparticle suspensions were prepared by controlled reduction of HAuCl4 using the sodium citrate method to obtain a nanogold-mercaptopropyltrimethyloxysilane (MPTS)–silicate–tetraethylothosilicate (TEOS)-capped particle solution. The nanoshells were formed when directly reacted with a 10-4 M calcium phosphate ion solution. The median nanoparticle diameter was observed to be 15 nm. The MPTS–silicate–TEOS–functionalized nanoshell more effectively formed a glass shell as compared with a nonsilicate nanoshell. The changes in the surface morphology and composition were observed by a scanning transmission electron microscope equipped with energy-dispersive X-ray spectroscopy. As seen using EDS, the nanoshell was in a glass phase with CaO-poor layers.